package dkim

import (
	"bytes"
	"context"
	"crypto/rand"
	"os"
	"path"
	"testing"

	"postern/internal/db"
	"postern/internal/persistence"

	"go.turscar.ie/dkim2"
)

type lookup struct {
	pubRecord string
}

func (l lookup) LookupTXT(_ context.Context, _ string) ([]string, error) {
	return []string{l.pubRecord}, nil
}

func TestSign(t *testing.T) {
	d := setupTestCommand(t)

	pubRecord, err := d.Add(t.Context(), "sel1", "example.com")
	if err != nil {
		t.Fatal(err)
	}
	err = d.SetEnabled(t.Context(), "sel1", "example.com", true)
	if err != nil {
		t.Fatal(err)
	}

	signedMessage, err := d.Sign(t.Context(), []byte(exampleMessage), "<raphael@example.com>", []string{"<someone@example.net>"})
	if err != nil {
		t.Fatal(err)
	}

	result := dkim2.Verify(t.Context(), bytes.NewReader(signedMessage), dkim2.VerifyOptions{
		IgnoreTimestamp: false,
		Resolver:        lookup{pubRecord},
		MailFrom:        "<raphael@example.com>",
		RcptTo:          []string{"<someone@example.net>"},
	})

	if result.Err != nil {
		t.Fatal(result.Err)
	}
}

func setupTestCommand(t *testing.T) *DKIM {
	t.Helper()
	f := t.TempDir()

	mkeyPath := path.Join(f, "masterkey")
	secretKey := make([]byte, 32)
	_, _ = rand.Read(secretKey)
	if err := os.WriteFile(mkeyPath, secretKey, 0666); err != nil {
		t.Fatal(err)
	}

	p, err := persistence.New(persistence.Config{
		BlobRoot:      path.Join(f, "blobs"),
		MasterkeyFile: mkeyPath,
	})
	if err != nil {
		t.Fatal(err)
	}

	posternDB, err := db.OpenDB(&db.Config{
		DBPath: path.Join(f, "meta.db"),
	})
	if err != nil {
		t.Fatal(err)
	}

	dkim := New(&Config{
		DB:          posternDB,
		Persistence: p,
	})
	return dkim
}

var exampleMessage = `Message-ID: <WIULIIOKPTXYAOVEIXQJJ@p25.dev>
From: "aw@example.com" <aw@example.com>
To: <raphael@p25.dev>
Subject: Hello from Postern!
Date: Sat, 18 Jun 2005 01:57:22 +0100

Hello test message.
`